<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>边框样式演示</title>
    <style>
        #d1{
            /*上边框*/
            border-top: 5px solid black;
            /*左边框*/
            border-left: 5px double red;
            /*右边框*/
            border-right: 5px double blueviolet;
            /*下边框*/
            border-bottom: 5px dashed pink;
            width: 150px;
            height: 150px;
        }

        #d2{
            border: 5px solid pink;
            /*设置边框弧度*/
            border-radius: 25px;
            width: 150px;
            height: 150px;
        }
    </style>
</head>
<body>
    <div id="d1"></div>
    <br/>
    <div id="d2"></div>
</body>
</html>